The first you learn: When I began Jiu jitsu it was standard practice to begin the study of guard with closed guard. There is a lot of wisdom to this. Closed guard has good value as a self defense position and that was an important consideration at that time as Jiu jitsu was closely linked to early MMA and fighting in general. As my experience as a coach grew I came to question whether closed guard was always the best choice for the first guard position for everyone. I always noticed that most beginner students had an easier time becoming effective from half guard than they did from full guard. Moreover closed guard tended to favor the longer legged athletes over short limbed athletes. Half guard seemed to work equally for all body types. In addition, half guard integrated extremely well with and allowed students to easily transition from a defensive elbow directly into half guard offense. Ultimately I came to believe that there is no one guard that ought to be learned before all others. Like everything in , different people will gravitate towards what they are best suited for. I therefore don't dictate what kind of guard comes first but rather show a variety of fundamental guards (nothing crazy at beginner level) and let people decide whether they prefer guards based on outside control such as closed guard, or control such as butterfly guard or a mix of both, such as half guard. In the end, you're going to have to learn all the various guard positions to some degree, which one you learn first doesn't seem to affect long term development that much, so start with the ones best suited to your body. The main thing is that you gain COMPETENCE THAT LEADS TO CONFIDENCE in your bottom game as early as that you overcome quickly our natural trepidation about fighting from tough opponents.